1. Field
This disclosure generally relates to a pipelined bus architecture and protocol and various particular aspects thereof.
2. Description of Related Art
With the increasing complexity and demands of software applications, there is demand for processors to provide increased throughput and bandwidth. There may be one or more resources which can limit computer performance, such as input/output (I/O) speed or bandwidth, memory size, etc. One resource that often limits or throttles computer performance is the speed and bandwidth of a bus such as a processor bus (also referred to as a front side bus), which is the bus provided between one or more processors and the chipset. Some bus prior art bus protocols provide support multi-phase pipelined transaction schemes for the processor bus. For example, some Pentium® processors such as the Pentium Pro® processor, Pentium® II processor, and the Pentium® III processor (hereafter “P6 bus protocol processors”) from Intel Corporation and chipsets that communicate with such components support an advanced multi-phase pipelined bus protocol. Various details of the bus protocols for the P6 bus protocol processors are found in the Pentium Pro® processor, Pentium® II processor, and the Pentium® III processor Family Developer's Manuals. For example, the P6 bus protocol is described in the Pentium® II Processor Developer's Manual (see, e.g., Chapter 3), October, 1997, Intel document number 243502-001, available from Intel Corporation of Santa Clara, Calif. as well as Pentium® Pro and Pentium® II System Architecture, by Tom Shanley, December 1997.
Other processors have altered the data transfer protocol by increasing the data transfer rate using a double-pumped, source synchronous protocol. See, for example, PCT publication WO 99/36858. Additional changes to improve various bus characteristics such as bus throughput and/or reliability may be desirable.